Minimum tillage toolbar and method for using same

ABSTRACT

A minimum tillage farm implement capable of being used for plowing, cultivating, planting and insecticide and herbicide and fertilizer application, which includes a tool bar frame having three parallel spaced apart laterally positioned tool bars held together by detachable interconnecting frame members. Coulters, chisel plows and discing pairs are mounted in series to the front tool bar. Variable width rototillers are attached to the middle tool bar and planters are attached to the rear tool bar, both serially aligned with the discing pairs. The coulters, chisel plows, discs and rototillers prepare a fine seed bed, even in stalks and stubble, to allow beneficial planting of row crop seeds by the planters. In a second mode the front and rear tool bars are detached leaving only the middle tool bar with rototillers, which can be adjusted for width and position to perform as cultivators of the areas between adjacent seed beds.

This is a continuation of co-pending application Ser. No. 443,442 filedon Nov. 22, 1982, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to minimum tillage farming equipment, moreparticularly to minimum tillage farming implements which performmultiple functions simultaneously and can be used in different modes.

In the ever continuing search to balance increased agriculturalproduction against environmental stewardship, and to conquer theeconomic barriers of ever-increasing fuel, equipment and material costs,minimum tillage farming has become an attractive alternative toconventional row crop farming methods.

Traditional row crop farming is based upon multi-pass operationsbeginning with preparing the field for planting and ending with theharvesting of the crop. It is not uncommon for some farmers to make fiveor more passes over a given field before harvesting includingconventional plowing or chisel plowing, discing, applying chemicals andfertilizers, planting and cultivating. The costs in fuel, equipment, andsupplies and materials are evident; while the more intangible costs oflabor, time, soil stress and soil erosion have risen to be significantconcerns.

Compaction of the soil also results and has been found to reduceproductivity significantly. Research has shown that something asseemingly innocent as a footprint can compact soil enough to inhibitplant growth. Compaction by the large, heavy equipment of today produceswhat is called "hardpan" which can cut productivity by 50% or more.

Minimum tillage methods and equipment have been in use and practiced fora number of years, but the economic and environmental pressures ofrecent times have prompted their adoption on a wide scale basis. Asexplained above, minimum tillage attempts to minimize the number ofground-working implement passes over a given field to reduce fuel,labor, equipment and environmental costs.

The difficulties with minimum tillage farming are many and diverse.Among the major problems are first, finding and developing equipmentwhich works effectively and efficiently in the minimally tilled ground.The equipment must be specialized and strong to attack the hardenedstalk and stubble filled ground. Furthermore, it is extremely difficultto produce an adequate seed bed when the ground is not worked over anumber of times.

Moisture concerns and weed control are additional significant problemsthat are encountered in minimum tillage farming methods. Compoundingthis problem is the ever present obstacle of clogging of the equipmentby the remnant trash in the field.

Because weed control is so important in minimum tillage farming, bothchemical herbicide incorporation and positive weed control are problemswhich must be conquered.

Some attempts have been made to conquer these problems by utilizingspecialized equipment, some being partially or wholly powered byindependent engines, which prepares the soil for an additional pass byconventional planting equipment. Others have attempted to combine thesoil preparation implements and planters for one pass planting. All ofthese attempts still do not overcome one or more of the problemsmentioned above.

Additionally, present minimum tillage equipment do not provide adequatemultiple-use flexibility, such as utilizing parts of the all-in-onetillage/planting implement for subsequent specialized uses such ascultivating.

It is therefore an object of the present invention to provide a minimumtillage farm implement which performs all necessary row crop operationsup to harvest with savings of time and labor, fuel, equipment costs andloss of soil.

A further object of the invention is to provide a minimum tillage farmimplement which both prepares a good seed bed for the planting of rowcrops and plants the crop in one pass of the field.

A further object of the invention is to provide a minimum tillage farmimplement which utilizes conventional planting units for the planting ofthe row crops.

Another object of the invention is to provide a minimum tillage farmingimplement which provides effective and efficient incorporation ofherbicides into the seed bed while sufficient moisture is present in thesoil to enhance the effectiveness of the herbicide and whileadditionally reducing the amount of herbicide used.

A further object of this invention is to eliminate hardpan problems byplacing the seeds directly behind a chisel plow.

A further object of this invention is to apply fertilizer during thefield trip in which the crop is planted.

Another object of the invention is to provide a minimum tillage farmimplement which can be easily converted to provide positive weed controlas a power cultivator.

A further object of this invention is to provide a power cultivatorwhich will not plug with soil or crop trash or residue, will providepositive weed control between the rows and will reduce soil erosion byleaving a mulch of trash and dead weeds and grass between the rows.

A further object of this invention is to provide a power cultivator thatdoes not create ridges between the rows as it passes through the field.

A further object of this invention is to provide a minimum tillage farmimplement which does not clog or build up with trash or soil.

A further object of this invention is to provide a minimum tillage farmimplement which, by reducing the required number of trips over a field,prepares a seed bed with the correct amount of soil moisture necessaryfor optimal germination and growth.

Another object of this invention is to provide a minimum tillage farmimplement which is powered by the power takeoff of the tractor pullingthe implement.

A further object of this invention is to provide a minimum tillage farmimplement which can be readily transported and readily turned around infields.

Another object of this invention is to provide a minimum tillage farmimplement which is adjustable for providing variable width seed bedpreparation and variable width cultivator coverage.

A further object of this invention is to provide a minimum tillage farmimplement which prepares a seed bed and plants seeds in between lastyear's rows and does not disturb last year's stalks or stubble andencourages weed growth outside of the newly formed seed beds, thusfurther reducing soil erosion.

A further object of this invention is to provide a minimum tillage farmimplement which is durable, easy to service and maintain, easy toadjust, and is economical.

Additional objects, features, and advantages of the invention willbecome apparent with reference to the accompanying specification anddrawings.

SUMMARY OF THE INVENTION

This invention utilizes a tool bar frame upon which is mounted aplurality of sets of ground working implements which till and plant rowcrops in one pass of the field. The implement is attached to aconventional three-point hitch of an agricultural tractor and utilizesconventional planting units to plant the seeds.

The ground working tools of each set are arranged serially one behindanother along the direction of travel of the implement, each setcomprising a coulter means, a plowing means, a discing means, arototilling means, and a planter unit, in that order. The coulter means,plowing means, and discing means are attached to the front tool bar;each set being spaced apart along the front tool bar to define thelocation of the rows of the crops to be planted. The rototilling meansare attached to the second tool bar while the planting units areattached to the third bar both in line with the tools on the front toolbar.

The coulter means splits and slices the untilled ground directly infront of the plowing means which further loosens the ground and shattershardpan that may exist, to enhance root growth of the seeds which are tobe planted along that line. Discing means, directly behind the plowingmeans, are angled so that the channel plowed by the plowing means iscovered up and somewhat levelled. The rototilling means then passes andefficiently and effectively processes the soil so that an even, uniformporous seed bed is formed. The conventional planter unit then forms afurrow, deposits the seeds, and covers up the seeds.

The specialized structure of the tool bar frame allows the front andrear tool bars to be detached from the middle tool bar, leaving themiddle tool bar with the rototillers to be used as power cultivatorsonce the planted crops have grown to a sufficient level. The width ofcoverage of the rototillers is adjustably variable by adding or removingtines of each unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of the invention in its planting modeshowing the relative depths to which the ground working tools functionin the ground and is taken along lines 1--1 of FIG. 2.

FIG. 2 is a partial plan view of the invention in the planting mode.

FIG. 3 is a top view showing only the ground contacting parts of theinvention in its planting mode except for the planter drive wheels.

FIG. 4 is a top view of a six row embodiment of the invention in itsplanting mode.

FIG. 5 is a top view of a six row embodiment of the invention in itscultivator mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In reference to the drawings, and particularly FIG. 1, there is shown aminimum tillage farm implement 10 in accordance with the invention. Atool bar frame 12 provides the basic support for the various groundworking tools which make up the implement. Tool bar frame 12 can be madeup of square 2 inch by 2 inch or 3 inch by 3 inch tool bars. The toolbar steel stock can vary in size in accordance with the load put onindividual frame members. The implement 10 is attached to three-pointhitch 15 (shown in FIGS. 1. 4 and 5), pulled by tractor 14 and utilizespower take-off (PTO) 16 and hydraulic lines (not shown) of tractor 14for various operational functions.

FIG. 1 shows the structural relationship of the various ground workingtools and their positions in the soil while in use. The same combinationof elements exists for each row of crop to be planted, and in thepreferred embodiment a six row implement is disclosed.

The first ground working tool is a rolling coulter 20 which is attachedto front tool bar 22 of tool bar frame 12 by mounting means 24. Thecoulter itself is hingably attached to mounting means 24 but is dampenedby spring 26 which is attached at opposite ends to mounting means 24 andcoulter 20 respectively Coulter 20 comprises a round, flat metal disc 28which is rotatably secured to supports 30 which in turn are hingablyconnected to mounting means 24. Coulter 20 splits and slices theuntilled ground it encounters and most importantly cuts and slices anycrop trash that exists from last year's crops which significantly detersany clogging of the chisel plow by the trash.

Rolling coulter 20 is positioned so that upon striking obstacles in theground and hingeably moving upward it does not come in contact withfront tool bar 22.

Disc 28 is generally adjusted to cut through the soil at a depth ofapproximately 3", the disc being approximately 22" in diameter so thatit can effectively cut through even large, heavy trash. Spring 26 biasesdisc 28 into the ground yet allows it to be resilient to obstacles suchas rocks in the soil.

Located directly behind coulter 20 is chisel plow 32 which is attachedto front tool bar 22 by mounting means 34. In the preferred embodiment,chisel plow 32 is made of spring steel. It thus will be resilient to thedrag and friction it encounters in the ground. Additionally, spring 36,attached at opposite ends to chisel plow 32 and extension arm 37, urgesplow 32 forward so that a jerking-type motion is produced by plow 32 asit moves through the soil. There is adequate clearance (generally 5 to 7inches) between coulters 20 and chisel plows 32 to prevent clogging ofsoil or trash. Chisel plow 32 is swept back, extending approximately6-9" into the ground, and falls directly in the path cut by disc 28. Thespring steel construction provides chisel plow 32 with resiliencyagainst rocks and other obstacles. Chisel plow 32 is swept back so thatthe hard compacted soil is effectively broken up but not kicked up, sothat the moisture in the soil is retained.

Chisel plow 32 can also have replaceable wear plates at its lower end tofacilitate economical replacement of those plates when they become worn.

The small furrow produced by chisel plow 32 is covered and levelled bydiscs 38 and 40. Discs 38 and 40 are rotatably mounted on axles 42 whichare attached to lower arms 44. Lower arms 44 are adjustably connected atelbow members 46 to upper arms 48 which are adjustably attached tomounting means 50 which are attached to front tool bar 22. The fore andaft adjustability of discs 38 and 40 by elbow members 46 can beaccomplished by the structure of elbow members 46 shown in FIG. 2. Thelower ends 52 of upper arms 48 can be of hemispherical shape, as can theupper ends 54 of lower arms 44. These hemispherical ends 52 and 54 haveteeth-like serrations along their edges so that when mated and securedby bolt 56 and nut 58, the mated serrations secure the hemispheres 52and 54 at that attitude, which hold lower arms 44 and discs 38 and 40 inthe desired positions relative to chisel plow 32.

Alternatively, adjustable elbows could be located at axles 42 of discs38 and 40 so that one-piece arms extend from tool bar 22 to axles 42.Other adjustment variations can also be used.

Discs 38 and 40 are generally positioned so that they engage the groundto a depth of 2". They are also oriented so that they push the soilwhich has been disturbed by chisel plow 32 back over that narrow furrowand also generally level the ground for proper herbicide incorporationby the rototiller. As can be seen in FIG. 2, the front edges of disc 38and 40 are spread apart wider than the rear edges for this purpose.Discs 38 and 40 are approximately 22 inches in diameter in the preferredembodiment.

Both rolling coulters 20 and discs 38 and 40 can have conventional discscrapers (not shown) to clean and help promote cleaner cutter action ofthese implements.

Following discs 38 and 40 are rototillers 60 which are attached tomiddle tool bar 62. Referring again to FIG. 1, it can be seen that theattachment to middle tool bar 62 is accomplished by means of upperparallel arms 64 and lower parallel arms 66 on both sides of eachrototiller 60. The forwardmost ends of parallel arms 64 and 66 attachhingably to mounting means 68 which in turn is attached to middle toolbar 62. The rearwardmost ends of lower parallel arms 66 are attached tothe supporting structure of opposite ends of the axle 80 of rototiller60 to provide maximum support, while the rearwardmost ends of upperparallel arms 64 are attached to opposite sides of housing 70 ofrototiller 60. The parallel upper and lower arms are hingably attachedat both ends to allow the rototiller to "float" while at the same time,the weight of the rototiller 60 provides adequate downward force forrototillers 60 to engage the soil to a sufficient depth. Spring loadedassists or weight can be added to meet varying soil conditions. In thepreferred embodiment, the length of the tines from tip to tip of therototiller is approximately 23". Rototillers 60 are powered from the PTO16 of the tractor which is linked to the rototillers by means of shafts,gear boxes and universal joints. In the preferred embodiment of theinvention, PTO 16 extends directly rearward from tractor 14, past fronttool bar 22 to a position just below middle tool bar 62, as can be seenin FIGS. 1 and 4. A gearbox 69 is located at that position and convertsthe lateral rotational forces by turning lateral shaft 71 which isrotatably mounted along the underside of middle tool bar 62. Aconventional friction torque limiter (not shown) is added to PTO 16 justahead of gearbox 69. Individual gearboxes (not shown) are thus mounteddirectly in front of each rototiller 60 and join rotatable connectingshafts 72 to gearboxes 76 located on housing 70 of rototillers 60.Shafts 74 then again convert the rotational power originating in PTO 16laterally to chain drive 78. Chain drive 78 turns sprocket 79 of axle80, as seen in FIG. 3.

Because rototillers 60 are powered from PTO 16 of tractor 14, they canbe rotated at various speeds by varying the speed of the tractor engineor by changing gears in gearbox 69 which is advantageous for differenttreatments of the soil and for different types of soil and differenttypes of soil conditions.

Planter units 82 are connected to rear tool bar 84 by mounting means 86.Like rototillers 60, parallel attachment arms 88 and 90 connect planterunits 82 to mounting means 84. Additionally, a down pressure springattachment 92 is placed between arms 88 and mounting means 84 to aidsoil penetration if needed.

Planter unit 82 is of conventional structure having furrow openingmeans, seed delivery means and furrow closing means. Fertilizer andinsecticide can be applied by planter unit 82 as part of the plantingaction. This fertilizer and insecticide is stored in bin 95 whereas theseeds are stored in bin 94. It can be seen in FIG. 2 that planter units82 are driven by chain 96 which is connected to drive shaft 98. Liftassist assemblies 100 which include 360° rotatable wheels 102 are alsoattached to rear tool bar 84 at two centered locations. Duringtransport, lift assist assembly 100 rises to a height whereby none ofthe ground working tools engages the ground. Tandem lift assist assembly104 attaches to opposite sides of tool bar frame 12 and utilizes 360°rotatable wheels 106 and 108 and floating axle construction to furthersupport the implement during turning and transport.

FIG. 3 shows how the ground contacting parts of the invention in theplanting mode work the soil and plants the seeds along a seed line 110which is approximately centered in the between-rows area of last year'scrop. Numeral 112 designates the depiction of last year's stalks andstubble. As can be seen, coulter 20 is directly followed by chisel plow32 along seed line 110. Discs 38 and 40, in their angular orientation,then follow chisel plow 32. Tines 114, attached to axle 80 of rototiller60, cover the area approximately 10-12 inches wide and surrounding seedline 110. Planter unit 82 has furrow opening discs 116 and compactingwheels 118 which open a planting furrow in the fine rototilled soil andcompact the walls of the furrow in preparation for seed tube 120 todeposit seeds in the furrow. Finally, closing wheels 122 cover up theseeds with loose soil.

Implement 10 is adjustable so that it may be used in at least two modes.Mode 1 is depicted in FIG. 4 whereby the total structure described aboveis utilized in presenting a six row minimum tillage planter. Thecomponents are arranged so that the six sets of ground working tools areattached to tool bar frame 112. Stalks and stubble 112 is completelyuntouched by implement 10 in this mode whereas the ground inbetween istilled by coulters 20, chisels 32, discs 38 and 40, and rototillers 60.Planter units 82 then follow, depositing seeds 124 along seedline 110.FIG. 4 also shows planter drive wheels 126 which are connected by chainsto drive shaft 98 as seen in FIG. 2.

FIG. 5 shows the second mode of operation of implement 10. Front andrear tool bars 22 and 84 are removed by detaching front interconnectingframe members 128 and rear interconnecting frame members 130 from middletool bar 62. An extender tool bar 132 is then added to one end of middletool bar 62 and with it an additional rototiller 60. Tractor 14 is thenattached to middle tool bar 62 in a manner in which the sevenrototillers are positioned between the now planted rows 133 of crops sothat they may cultivate the trash and any weeds that have growninbetween new rows 133. To facilitate the shift of the rototillers ahalf a row over in the cultivator mode, a second gearbox 138 ispositioned along lateral shaft 71 so that upon hitching of tractor 14 tomiddle tool bar 62 in cultivator mode 2, PTO 16 can extend straight backallowing the seven rototillers 60 to be balanced. This allows PTO shaft16 to remain straight from tractor 14 to the tool bar frame 12regardless what mode the implement 10 is in. The width of coverage ofrototillers 60 can be determined by adding or subtracting tines 114 toaxle 80. Generally, a lesser number of tines 14 will be used when in theplanting mode and a greater number will be used to get maximumcultivation coverage in mode 2. Additionally, conventional stabilizingcoulters (not shown) can be added to the middle tool bar 62 to stabilizethe cultivator's direction of travel in the second mode.

In operation, the planting mode functions as follows. With particularreference to FIG. 3, it can be seen that after implement 10 has beentransported and lowered by three point hitch 15 and lift assistassemblies 100 and 104 to its operative position in the soil, coulters20 slice and cut through any trash along the seed lines. Chisel plows 32then cut and plow out narrow channels approximately 6-9" deep along seedlines 110. Disc pairs 38 and 40 subsequently cover and level the groundto either side of seed lines 110. Rototillers 60, rotating atcomparatively high revolutions per minute, break up and finely till thesoil to produce an even, level seedbed of fine, porous soil which iscapable of better moisture absorption than other methods. Planter units82 then follow and work as described above. At the end of each row, liftassist assemblies 100 and 104 are actuated, implement 10 is lifted fromits operative position, and tractor 14 and implement 10 are turnedaround and repositioned for another pass through the field. FIG. 4depicts implement 10 in the planting mode as it would appear inoperation. Implement 10 thus combines the processes of tillage andplanting into one pass, producing the cost saving benefits which havebeen described above.

Additionally, the preferred embodiment of the invention has the addedadvantage of efficiently and effectively incorporating herbicide intothe soil in bands in and around the seedbeds prepared by rototillers 60.This is accomplished by connecting a liquid herbicide supply via supplylines 134 to nozzles 136 inside of each housing 70 of rototillers 60.Herbicide supply tanks can be mounted on tractor on implement or ontrailing containers hitched to the implement. By utilizing suchstructure, the herbicide is shielded from wind, is sprayed only in thenarrow paths which become the seedbeds, and is thoroughly and optimallyincorporated into the soil by the rototiller 60. Additional shields (notshown) can be added to each end of tines 114 to provide uniformherbicide incorporation and to better provide for a level seed bed. Ithas been found that incorporation by rototillers is the most effectiveand most efficient manner of applying herbicides because the thoroughmixing of the soil and the precise, most beneficial depth ofincorporation can be controlled.

Likewise, insecticide and fertilizer can be applied either throughconventional planter units 82 or by other means which can be placed uponimplement 10. Anhydrous ammonia or liquid nitrogen can be applied bymounting hoses directly behind chisel plows 32. Supply tanks can becarried on tractor 14, on implement 10, or on trailing containershitched to the implement.

Pumps to convey herbicides or fertilizer can be powered by the tractor'shydraulic system or by rotational power from the tractor's powertake-off, as supplied to gearbox 69.

The second mode of implement 10, the cultivator mode, becomesoperational by removing front and rear tool bars 22 and 84 and hitchingtractor 14 to remaining middle tool bar 62. Additional tines 114 areadded to axles 80 of rototillers 60 to widen the coverage of rototillers60. Weeds are not a problem in the actual crop rows because of theeffective incorporation of herbicide when planting. In fact, weeds areencouraged to grow in between the rows during early stages of growth todeter wind and water erosion. At a suitable time after the crops havegrown, a pass is made with cultivator mode 2 of implement 10 with therototiller 62 operating at a comparitively lower revolutions per minuteso that the weed growth in between the rows is simply cut offapproximately just below ground level and the trash in the rows ismulched. This leaves additional ground cover, again deterring erosion,while at the same time cutting down the weeds.

Thus, with two passes, the crops have been effectively planted andeffectively cultivated. An additional cultivation may be desirable,otherwise no other field work is needed until harvest.

It is to be noted that mounting means 24, 34, 50, 68, and 86 can be anysuitable securing hardward adaptable to secure the ground working toolsto tool bars 22, 62, or 84. Securing hardware to accomplish this purposeis known in the art.

Conventional marker devices can also be hingeably mounted to oppositesides of tool bar frame 12 and have hydraulically-powered variable speeddiscs at their extreme ends. These markers can be dropped and pulledthrough non-planted ground to provide a marker line for the operator togauge straight rows with on the return pass of implement 10. Thevariable speed discs allow the operator to choose what rotational speedleaves the most visible mark in different trash, light and soilconditions. The discs would have angled edges to aid penetration in hardsoils or heavy trash.

Thus it can be seen the invention accomplishes at least all of itsstated objectives. It is to be noted that modifications and alterationscan be made while staying within the boundaries of the invention.

What is claimed is:
 1. A minimum strip tillage farm implement forpulling by a tractor means and adapted for single pass seed bedpreparation and planting of crop rows, as well as for operativeconnection or means for selective insecticide, herbicide and fertilizerapplication when in a first mode, and having a second mode for use as apower cultivator in-between said crop rows, said implement comprising:atool bar frame comprised of detachable removeable, interconnecting framemembers and spaced apart front, middle, and rear tool bars forattachment of a plurality of sets of ground working implements, saidtool bars being detachably adjoined by said interconnecting framemembers; in said first mode said tractor means being operativelyconnected by tractor connection means to a first position on said fronttool bar and each said set of ground working implements being aligned inseries along said front, middle and rear tool bars for preparation ofone crop row as follows, said front tool bar carrying at least trashcutting means, said middle tool bar carrying individually powered,individually floating rototillers to prepare a strip tillage seed bed,and said rear tool bar carrying detachable planters; and wherein saidfront and rear tool bars are removeable by detaching said detachableinterconnecting members at least from said middle tool bar to leave onlysaid middle tool bar and power rototillers for use in a second mode,said tractor means being operatively connectable by said tractorconnection means to a second position on said middle tool bar offsetfrom said first position on said front tool bar in a manner to allowoperation of said implement is said second mode as in-between-row powercultivators.
 2. The device of claim 1 wherein said front, middle andrear tool bars are generally parallel to each other and extendtransversely of the direction of travel of the implement.
 3. The deviceof claim 2 wherein said interconnecting members comprise elongated beamshaving flanges at opposite ends for receiving securing means whichsecures said interconnecting members to said tool bars.
 4. The device ofclaim 1 wherein said trash cutting means comprises a coulter means. 5.The device of claim 1 wherein said front tool bar carries in series acoulter means, a plowing means, and a discing means.
 6. The device ofclaim 4 wherein said coulter means comprises a plurality of coulterswhich have dampening means to allow said coulters to be resilient toobstructions encountered in the ground.
 7. The device of claim 5 whereinsaid plowing means comprises a plurality of chisel plows havingdampening means to allow said chisel plows to be resilient to obstaclesencountered in the ground, said chisel plows being aligned to traveldirectly through the line of travel produced by said coulter means. 8.The device of claim 5 whereby said discing means comprises a pluralityof disc pairs located behind and to either side of each said chiselplowing means, each disc of each said disc pair having dampening meansand being adjustable for depth and angular attitude of the faces of saiddiscs.
 9. The device of claim 8 wherein said discs of each said discpair are positioned so that the distance between the front edges of saiddiscs is greater than the distance between the rear edges so that saiddiscs cover and smooth the ground which has been passed over and plowedby said coulter means and said plowing means.
 10. The device of claim 1wherein said rotillers comprise a plurality of rototilling units eachhaving variable ground working width and each floating with respect tothe ground and having housings covering each rototilling unit.
 11. Thedevice of claim 1 wherein said rototillers are powered by operativeconnection to the power take-off of a tractor.
 12. The device of claim 1wherein said rototiller includes means for incorporating liquidherbicide into the soil.
 13. The device of claim 12 wherein said meansfor incorporating liquid herbicide into the soil comprises spray nozzleslocated inside said rototiller housings, said nozzles being connected toa herbicide supply which directs said herbicide into the ground as it isrototilled.
 14. The device of claim 1 wherein lift assist means areattached to said tool bar frame.
 15. The device of claim 14 wherein saidlift assist means comprise arms connected to said rear tool bar whichextend rearwardly to a wheel means which contacts the grounds, said armsbeing remotely adjustable to raise and lower said farm implement. 16.The device of claim 14 wherein said lift assist means comprise armmembers connected to opposite sides of said tool bar frame, said armmembers being connected to ground contacting wheels and being remotelyadjustable to raise and lower said farm implement.
 17. The device ofclaim 5 wherein said lift assist means further comprises arm membersconnected to opposite sides of said tool bar frame, said arm membersbeing connected to ground contacting wheels and being remotelyadjustable to raise and lower said farm implement.